1-1/√3 as the exact answer but books answer is (√3-1/√3+1)
what am i doing wrong?

Apr 6th 2009, 09:15 AM

stapel

Quote:

Originally Posted by jepal

Since Tan 45-tan 30=tan 15

Um... not actually. The value of tan(15) is the same as the value of tan(45 - 30), but not at all the same as the value of tan(45) - tan(15)! (Surprised)

Are you familiar with function notation at all? If so, then note that the tangent function is a function, so "tan(x)" means "f(x)", where the specific name of the function "f" is "tangent". Just as f(a + b) does not mean the same thing as f(a) + f(b), so also tan(45 - 30) does not mean tan(45) - tan(30).

To simplify tan(45 - 30), you have to use the angle-difference formula they gave you. (Wink)

Apr 6th 2009, 09:19 AM

jepal

Quote:

Originally Posted by stapel

Um... not actually. The value of tan(15) is the same as the value of tan(45 - 30), but not at all the same as the value of tan(45) - tan(15)! (Surprised)

Are you familiar with function notation at all? If so, then note that the tangent function is a function, so "tan(x)" means "f(x)", where the specific name of the function "f" is "tangent". Just as f(a + b) does not mean the same thing as f(a) + f(b), so also tan(45 - 30) does not mean tan(45) - tan(30).

To simplify tan(45 - 30), you have to use the angle-difference formula they gave you. (Wink)